The objective of this study is to asses the safety, tolerability and analgesic effects of rising doses of SNX-111, administered intrathecally to terminally ill patients who suffer from chronic pain and have had an unsatisfactory response to opioid therapy. SNX-111 is a new type of calcium channel blocker that specifically blocks N-type neuron-specific, voltage-sensitive calcium channels which are found at presynaptic nerve terminals. This is a multicenter study, where 30 patients are expected to enroll, 5 of which will be studied at Emory. Two patients have been evaluated. The protocol is currently being modified for resubmission to the GAC.